net.shibboleth.utilities.java.support.codec

Class HTMLEncoder

java.lang.Object

net.shibboleth.utilities.java.support.codec.HTMLEncoder

public final class HTMLEncoder
extends Object

An HTML encoder derived from the OWASP ESAPI project. The encoded output will be safe for an HTML interpreter as unsafe characters are translated into their safe equivalent.

See Also:

OSJ-69, org.owasp.esapi.Encoder, org.owasp.esapi.reference.DefaultEncoder, org.owasp.esapi.codecs.HTMLEntityCodec

Field Summary

Fields

Modifier and Type	Field and Description
private static Map<Character,String>	CHARACTER_TO_ENTITY_MAP Map from entity character to name.
private static String[]	HEX Initialize an array to mark which characters are to be encoded.
static char[]	IMMUNE_HTML Character set immune from HTML encoding.
static char[]	IMMUNE_HTMLATTR Character set immune from HTML attribute encoding.
static char	REPLACEMENT_CHAR Character to replace illegal characters.
static String	REPLACEMENT_HEX Hex to replace illegal characters.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	HTMLEncoder() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
private static boolean	containsCharacter(char c, char[] array) Utility to search a char[] for a specific char.
private static String	encode(char[] immune, String input) Encode a string for safe use in an HTML entity field.
private static String	encodeCharacter(char[] immune, Character toEncode) Encodes a character for safe use in an HTML entity field.
static String	encodeForHTML(String input) Encode data for use in HTML using HTML entity encoding
static String	encodeForHTMLAttribute(String input) Encode data for use in HTML attributes.
private static String	getHexForNonAlphanumeric(char c) Lookup the hex value of any character that is not alphanumeric.
private static Map<Character,String>	mkCharacterToEntityMap() Build an unmodifiable map from entity character to name.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

IMMUNE_HTML

@Nonnull
public static final char[] IMMUNE_HTML

Character set immune from HTML encoding.

IMMUNE_HTMLATTR

@Nonnull
public static final char[] IMMUNE_HTMLATTR

Character set immune from HTML attribute encoding.

REPLACEMENT_CHAR

@Nonnull
public static final char REPLACEMENT_CHAR

Character to replace illegal characters.

See Also:

Constant Field Values

REPLACEMENT_HEX

@Nonnull
public static final String REPLACEMENT_HEX

Hex to replace illegal characters.

See Also:

Constant Field Values

CHARACTER_TO_ENTITY_MAP

@Nonnull
private static final Map<Character,String> CHARACTER_TO_ENTITY_MAP

Map from entity character to name.

HEX

@Nonnull
private static final String[] HEX

Initialize an array to mark which characters are to be encoded. Store the hex string for that character to save time later. If the character shouldn't be encoded, then store null.

Constructor Detail

HTMLEncoder

private HTMLEncoder()

Constructor.

Method Detail

encodeForHTML

@Nullable
public static String encodeForHTML(@Nullable
                            String input)

Encode data for use in HTML using HTML entity encoding

Note that the following characters: 00-08, 0B-0C, 0E-1F, and 7F-9F

cannot be used in HTML.

Parameters:

input - the text to encode for HTML

Returns:

input encoded for HTML

See Also:

HTML Encodings [wikipedia.org], SGML Specification [w3.org], XML Specification [w3.org]

encodeForHTMLAttribute

@Nullable
public static String encodeForHTMLAttribute(@Nullable
                                     String input)

Encode data for use in HTML attributes.

Parameters:

input - the text to encode for an HTML attribute

Returns:

input encoded for use as an HTML attribute

encode

@Nonnull
private static String encode(@Nonnull
                    char[] immune,
                    @Nonnull
                    String input)

Encode a string for safe use in an HTML entity field.

Parameters:

immune - characters immune from encoding

input - the string to encode

Returns:

the encoded input

encodeCharacter

@Nonnull
private static String encodeCharacter(@Nonnull
                             char[] immune,
                             @Nonnull
                             Character toEncode)

Encodes a character for safe use in an HTML entity field.

Parameters:

immune - characters immune from encoding

toEncode - the character to encode

Returns:

the encoded character

getHexForNonAlphanumeric

@Nonnull
private static String getHexForNonAlphanumeric(@Nonnull
                                      char c)

Lookup the hex value of any character that is not alphanumeric.

Parameters:

c - the character to lookup.

Returns:

null if alphanumeric or the character code in hex.

containsCharacter

private static boolean containsCharacter(@Nonnull
                        char c,
                        @Nonnull
                        char[] array)

Utility to search a char[] for a specific char.

Parameters:

c - the char

array - the array

Returns:

whether or not the array contains the char

mkCharacterToEntityMap

@Nonnull
private static Map<Character,String> mkCharacterToEntityMap()

Build an unmodifiable map from entity character to name.

Returns:

unmodifiable map from entity character to name